Many conventional temperature control systems in use today comprise a single heating and/or cooling means combined with duct means to distribute temperature controlled air throughout a building or other enclosure. Typically, the duct means will comprise several distinct ducts or branches leading to various portions of the enclosure. Ideally, the ducts are arranged and dimensioned in such manner that the air distribution to the various portions of the enclosure will maintain the enclosure or building at a relatively constant temperature throughout. The temperature at which the building is to be maintained is generally controlled by a single thermostat located at a position which is presumed to be representative of the temperature throughout the building.
In actual use, the ideal situation described above cannot be achieved. Due to structural limitations, the ducts running through the building will generally comprise many bends, deviations, and irregularities which will result in somewhat unpredictable impedences to flow therethrough. Exterior conditions, such as solar radiation and wind, will affect each portion of the building in a different manner. Also, warmer air will naturally tend to rise to the upper portions of the building, while cooler air tends to drop to the lower portions. These factors all contribute to creating a temperature imbalance among respective portions of the building or structure. Additionally, if differing types of activities are carried out in the various portions of the building, the varying activity levels will further contribute to the temperature imbalance.
Quite apart from the fact that a temperature imbalance is often created in a situation when it is desirable to have balanced temperature conditions, it is often desirable to segregate a building or structure into distinct zones, maintaining a different temperature level in each zone. The ordinary single source heating or cooling systems in use at present are not capable of maintaining these distinct temperature levels in a predictable and controlled fashion.
One method which has been used to alleviate the problems described above has been to provide individual heating devices in various portions of a building. A standard system of this nature might involve the use of individual radiant heaters in separate rooms or zones within the building, each heater having its own thermostat control. This technique is generally effective to provide desired temperature levels in the respective heating zones, but installation of such a system is relatively expensive, and operation of radiant heaters is generally not energy efficient. Also, the presence of a heat source in an area which is occupied or utilized for other activities generally presents an unacceptable fire hazard.
Another method commonly used to attempt to maintain proper temperature balance is the incorporation of dampers into the ducts of a forced air heating or cooling system. By adjusting the degree to which the dampers in various ducts are opened, one may regulate the relative amounts of air flow through the respective ducts. In this manner, one may attempt to maintain the temperature levels in the various zones of a building at approximately equal values. The manner in which the various dampers must be adjusted in order to maintain a proper temperature balance is generally a matter of guesswork. It is necessary, by trial and error, to continually adjust and readjust the various dampers until one achieves a satisfactory air distribution throughout the building or structure. If one wishes to incorporate automatically operated or controlled dampers in such a system, this technique suffers from the additional drawback that such automatic dampers are generally very expensive motor operated devices.
Accordingly, it is an object of this invention to overcome the drawbacks associated with prior art heating and cooling systems.
Particularly, it is an object of this invention to provide means by which one may maintain, in a controlled fashion, a desired temperature balance throughout a building or structure.
It is an object of this invention to provide means by which one may maintain differing temperatures in different portions of a building utilizing a single heating or cooling means.
It is an object of this invention to provide a low cost multizone heating or cooling system utilizing a single heating or cooling means.
It is a further object of this invention to provide means for adapting a single heating or cooling means to multizone use which may be incorporated into newly installed units or retrofitted into existing systems.
It is a further object of this invention to provide a low cost automatically controlled damper means.
It is yet another object of this invention to provide automatic damper means which is compatible with existing forced air heating or cooling systems.
It is an object to provide such damper means which may be manufactured and installed at very low cost.